1. Field of the Invention
The present invention relates in general to automotive vehicle steering columns and more particularly a tilting collapsible steering column constructed so as to absorb impact energy upon collision of a vehicle.
2. Description of the Prior Art
A tilting collapsible steering column is disclosed in Japanese Provisional Patent Publication No. 50-60526 which is assigned to the same assignee of this application. In this steering column, a tilt bracket welded to a column jacket is movably supported upon an upper clamp and formed with a slit or cut near the place for connection with the column jacket. With the tilt bracket breakaway structure, it is intended that in collision the tilt bracket shears near the cut while absorbing the impact of the driver hitting the steering wheel as the driver is thrown into it.
A problem of the tilt bracket breakaway structure is that it cannot absorb the impact energy efficiently since the impact load cannot be transferred to the bracket breakaway structure efficiently.
Another problem is that the impact energy which the breakaway structure can absorb changes largely from the beginning to ending of a collision, i.e., it cannot effect a smooth and stable impact energy absorbing characteristic.